Hello everyone. Can someone clarify the purpose of the MVM block when paired with a 2#1111_1111_1111_1111 mask? I am hoping for a clearer explanation to avoid confusion. I thought I understood how it worked, but now I am unsure. The documentation is not helping either. Your insights would be greatly appreciated. Thank you.
Logix is adamant about not wanting the mask to change, which some may find frustrating and unproductive. However, is there any benefit to using a MVM with a mask value of -1 (essentially no masking) instead of a MOV in this scenario? This involves an analog signal that typically does not require masking, as opposed to a series of Boolean values. It seems that the example provided still lacks clarity, unless the author also encountered the same confusion.
dalporto inquired about the potential benefits of using a MVM with a -1 mask value (essentially not masking anything) rather than a MOV in a specific scenario. Will the MVM handle bits differently when the data type or width in bits of the Source and Dest variables differ?
The MIPREG_Data_5[1] is confirmed to be a DINT, whereas the ProSoft Integer MCM08.WriteData[641] is an INT. This distinction is reflected in the mask being 65535 instead of -1. This adjustment ensures that the value is limited to 16MW to prevent the receiving device from displaying a 1MW setpoint when the actual setpoint is higher, such as 17MW. This clarification makes the process more logical and understandable.
In the case of the SP exceeding 16MW, a clamp is applied to ensure that the receiving device does not receive a value like 1MW when the actual SP is higher, such as 17MW. This mechanism helps maintain consistency in the values transmitted. If the value exceeds 65535, it resets to the appropriate range, accounting for the overflow in the DINT. The purpose of this feature seems to be converting the DINT to an INT. It is uncertain what would occur if only a MOV instruction was used. Despite this, it appears to function correctly, although there may be discrepancies with the receiving device.
The MVM instruction is designed to perform bitwise operations in PLC programming. It is used to manipulate bits in a specific way: it calculates the result by combining the Source and Mask using AND and OR operators, and then applying the NOT operator to the result combined with the Dest value. The destination word is updated with the final result of this operation. In scenarios where a negative integer value is moved into a DINT variable, sign extension occurs. This means that the high 16 bits of the DINT will be filled with 1-valued bits. For example, using a mask value of 2#1111_1111_1111_1111 in the MVM instruction leaves the high 16 bits of the Dest DINT unchanged.
Hello! The MVM block or Memory Value Modifier Block is designed to help modify specific bits in your register. When paired with the mask 2#1111_1111_1111_1111, it means you're targeting all 16 bits of your register to be potentially altered. This binary mask works as a filter, where each "1" indicates an active or "open" bit and a "0" points to an inactive or "closed" bit. When all bits are "1", any change in the MVM block will affect the whole register. It's similar to a stencil that guides where changes are made. It can get tricky, so it's great you're asking questions!
Hey there! The MVM (Matrix Vector Multiply) block is designed to efficiently handle operations involving matrices and vectors, particularly when you want to multiply a matrix by a vector and apply a mask like the 2#1111_1111_1111_1111 to selectively ignore or include certain elements. In your case, that mask allows you to focus on specific bits of the input, effectively filtering which parts of the vector are used in the multiplication, which can be super handy for optimizing performance or memory usage. If you have a particular scenario or example, feel free to share it; sometimes that can help clarify things even more!
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Answer: - The Rockwell MVM block, when paired with a 21111_1111_1111_1111 mask, is used for specific data manipulation and processing tasks in industrial automation applications.
Answer: - The MVM block performs bitwise operations on data based on the binary mask 21111_1111_1111_1111, which helps in filtering or modifying specific bits within the data.
Answer: - The complexity of the MVM block's operations and the lack of clear documentation can lead to confusion even for those who have a basic understanding of its purpose.
Answer: - Different perspectives and explanations from others can provide clarity and a deeper understanding of how the MVM block functions with the specific binary mask, helping to overcome confusion and misconceptions.
Answer: - Seeking guidance from experienced users, consulting Rockwell's official documentation, or
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